In the past, measuring toxic organic contaminants in blood on a wide scale level has presented a challenge due to concentrations that are near-to or below detection limits. Targeted MRM assays could overcome many of those challenges, but is only feasible for a limited number of targets in a single analysis. Targeted analyses are useful when you know what you are looking for, but for scenarios where exposure is unknown, or where previously unidentified contaminants could be present, it may be more useful to identify non-target contaminants. To identify non-target contaminants, full-scan acquisitions using mass spectrometers with high enough resolving power to identify non-target contaminants would be more useful. Full scan acquisitions can sometimes sacrifice sensitivity in order to capture additional spectral information. To address this, we have developed a method to enhance sensitivity using zone compression. In this talk, we present up to 10x signal enhancement using cryogenic modulation during a GC separation paired to the Xevo G2-XS QTof Quadrupole Time-of-Flight Mass Spectrometer with an APGC ion source (Waters). A workflow using Waters UNIFIsoftware to identify non-targeted contaminants was created and validated using dust samples and standards. The methods presented will demonstrate the real potential for non-targeted screening of toxic organic contaminants in humans and wildlife.

The presented study focuses on the analysis of plasma samples that were obtained from native populations and extracted to analyze persistent organic pollutants (POPs). Samples were analyzed on the APGC couple with the XEVO G2-XS QTof operated in a data independent mode which produced precursor and product ion information in a single acquisition. Data was first subjected to a targeted data analysis to assess the presence of ubiquitous POPs or suspected emerging ones in the samples and to assess the distinctive trends among the different communities of native populations. Following this targeted approach, a non-targeted, multivariate technique was used to identify compounds that were prominent in each community. These compounds were then subjected to database searches in order to identify these markers of interest. Proposed identifications from both targeted and non-targeted approaches will be presented.